Comment 5 for bug 1163886

It is not "fix" per se. But I have found a workaround, if you need to use software-center rather than just using terminal tools like dpkg and apt, which is what I do. Also, I use gdebi for GUI based installing of packages I download with my browser, as it is much more slim than the Ubuntu Software Center.

Anyway, the fix/workaround to get it to load for tyhe time being is to just give it elevated privleges. So like this: "sudo software-center" without quotes in the terminal, and it will launch that for you